@color: pink;
@divide: 15;

@media screen and (min-length:320px) {
  html {
    font-size: (320px / @divide);
  }
}

@media screen and (min-length:750px) {
  html {
    font-size: (750px / @divide);
  }
}

div {
  background-color: @color;
}
